Margaret Thatcher's big trip to China in 1982 to open talks on the future of the then British crown colony of Hong Kong was blighted by a row over the menu for the official banquet she was to host for the Communist party leadership.

The Foreign Office wanted to serve the 75 yuan-per-head set menu, which included sea slugs and fish lips, while Thatcher thought the 50-yuan option was sufficient as long as bread, butter and strawberry jam was deleted as a dessert option.

Thatcher's personal papers show that despite the fact this was the first visit by a serving British prime minister to Beijing, she spent an astonishing amount of time fretting over the banquet before she had even left London.

She was anxious "to do everything possible" to make the British "return banquet" for 120 guests a rather special occasion. It was to be held in the prestigious but cavernous Great Hall of the People.

She even instructed Downing Street officials to investigate whether they could take out special silver centrepieces and candlesticks for the tables. The Royal Navy was reluctant to let her have its best silver, pointing out it was extremely valuable and would have to be specially crated if it were to be moved from Portsmouth. But their objections were overcome and the silver was transported to London and laid out in Lancaster House so that Thatcher could choose which pieces to take to China.

The next problem was the menu. Struggling between "the conflicting calls of economy and prestige", she decided on the cheapest 50 yuan-a-head option as long as it was supplemented by Scottish smoked salmon flown in from London to provide some style.

The Foreign Office thought this a great mistake. Sir Percy Cradock, the British ambassador in Beijing, weighed in. "We cannot have a memorable banquet in the Great Hall of the People without paying for it," he wrote in a telegram to London. "The 50 yuan-a-head menu lacks shark's fin and sea slugs, both delicacies to a Chinese palate which would be conspicuous by their absence on an occasion such as this. Nor should we attempt to skimp on the drinks which are traditional here (mineral water, beer, fizzy orange and maotai)."

Thatcher insisted on the 50-yuan menu but balked at its inclusion of bread, butter and strawberry jam for dessert, over-ruling Foreign Office objections that it was still considered a great treat. She decided in favour of fruit salad instead.

In the event the preparations were overshadowed by the fact that only one senior member of the Chinese leadership turned up for the banquet, which ended sober and early. The rest were at another banquet in the same building hosted by the North Korean leader, Kim Il-sung, where the toasts to "militant friendship" went on late into the night.